In recent years, there have been increasing demands for global environmental conservation. Under the circumstances, refrigerator-freezers for household uses, or air conditioners have been developed to achieve energy saving, and demands for attention to environments in which refrigerator-freezers and the air conditioners are used have been increasing.
To address such attention to the environments, there is known a sealed compressor in which an extending section is provided in the vicinity of an opening of an exit pipe placed inside of a suction muffler by suppressing suctioning of oil to a compression chamber to mitigate a noise (see e.g., Patent Literature 1).
Hereinafter, the conventional sealed compressor will be described with reference to FIGS. 6 to 8. In description below, a relationship of upper and lower sides is on the basis of a state in which the sealed compressor is placed in a normal position.
FIG. 6 is a longitudinal sectional view of the sealed compressor disclosed in Patent Literature 1. FIG. 7 is a cross-sectional view taken along B-B of FIG. 6. FIG. 8 is a cross-sectional view of a suction muffler of the sealed compressor of FIG. 6.
As shown in FIGS. 6 and 7, the sealed compressor disclosed in Patent Literature 1 includes a sealed container 2 and a compressor body 6. In a bottom portion of the sealed container 2, lubricating oil 4 is stored, and the compressor body 6 is elastically supported on the sealed container 2 by a suspension spring 8.
The compressor body 6 includes an electric component 10 and a compression component 12 disposed above the electric component 10. The electric component 10 is a DC brushless motor which includes a stator 14 formed by windings wound around stacked steel plates and a rotor 16 including permanent magnets 15 and is connected to an inverter circuit (not shown) by means of a conductive wire (not shown).
A shaft 18 of the compression component 12 includes a main shaft section 20 and an eccentric shaft section 22 extending above the main shaft section 20. The main shaft section 20 is rotatably mounted to a main bearing 26 of a cylinder block 24. The rotor 16 is fitted to the main shaft section 20. The shaft 18 is provided with an oil feeding mechanism 29 including a spiral groove 28 and the like formed on the outer surface of the main shaft section 20.
The suction muffler 46 is manufactured by molding resin such as PBT, and is retained between a valve plate 40 attached to the end surface of a cylinder 34 and a cylinder head 44 surrounding the valve plate 40. As shown in FIG. 8, the suction muffler 46 includes a muffling space 50, an inlet pipe 52, an exit pipe 54, and a discharge hole 56.
The inlet 52 is placed such that an opening 52a which is one end thereof opens in a muffling space 50 and a suction port 51 which is the other end thereof opens in an internal space of the sealed container 2. The exit pipe 54 is placed such that an opening 54a which is one end thereof opens in the muffling space 50 and the other end thereof is in communication with a compression chamber 42. The discharge hole 56 is provided in the lower portion of the muffling space 58.
The opening 52a of the inlet pipe 52 and the opening 54a of the exit pipe 54 are placed so that a flow direction of a refrigerant gas in each opening is horizontal. In the vicinity of the opening 54a of the exit pipe 54, an extending section 58 extending radially outward is provided.
Hereinafter, the operation of the sealed compressor disclosed in Patent Literature 1 configured as described above will be described.
Initially, the electric component 10 is actuated by an inverter circuit. According to the rotation of the rotor 16 of the electric component 10, the shaft 18 of the compression component 12 rotates. Then, the compression component 12 performs a predetermined compression operation.
The lubricating oil 4 is suctioned up from the bottom portion of the sealed container 2 up to the upper end of the shaft 18 by the oil feeding mechanism 29 while lubricating the constituents of the compression component 12, and is scattered in the internal space of the sealed container 2. The lubricating oil 4 scattered in the internal space of the sealed container 2 is suctioned from the suction port 51 into the muffling space 50 of the suction muffler 46 via the inlet pipe 52 along with the refrigerant gas. A portion of the lubricating oil 4 suctioned into the muffling space 50 adheres to the outer surface of the exit pipe 54 placed in close proximity to the exit of the inlet pipe 52.
The adhering lubricating oil 4 moves toward the opening 54a of the exit pipe 54, by the flow of the refrigerant gas flowing through the inlet pipe 52, but is blocked by the extending section 58. Thereby, the lubricating oil 4 drops downward to the bottom portion of the muffling space 50 and is discharged from the discharge hole 56 to outside of the suction muffler 46. As a result, it becomes possible to suppress unnecessary lubricating oil 4 from being suctioned into the compression chamber 42 through the exit pipe 54.